The present invention relates to trench metal-oxide-semiconductor (MOS) devices, and in particular, to trench MOS devices with Schottky diode and method for manufacturing same.
Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Trench MOS devices are typically employed as transistors in power integrated circuits. Trench MOS devices may be manufactured in parallel with conventional PN diodes in order to decrease the turn-on voltage of the device when forward biased. The threshold of the MOS transistor may be designed to be much less than the 0.6V turn-on voltage of the typical PN junction. The reduction in turn-on voltage translates into a smaller voltage drop for any given current and therefore, an overall power savings for the device.
In rectifier applications, the trench MOS devices may typically have a slow switching response time such that the PN junction may be fully biased at 0.6V for a portion of time prior to the trench MOS device responding and reducing the forward voltage. The higher the frequency of the switching, the more pronounced this characteristic may be and more power may be wasted.
Thus, there is a need for improved trench MOS devices. The present invention solves these and other problems by providing trench MOS devices with Schottky diode and methods for manufacturing same.